In a friction member such as a brake lining, disk pad, and clutch facing for automobile or industrial machinery use, in the past asbestos was used as the base material, but due to the environmental issues posed by asbestos, development of non-asbestos friction members has been desired. At the present time, friction members using, as alternative materials to asbestos, fiber base materials such as glass fiber, carbon fiber, aramid fiber, rock wool, ceramic fiber, and various steel fibers are being developed and used. Friction members using such a fiber base material are usually produced by adhering a resin composition containing a thermosetting resin or rubber ingredient etc. on the fiber base material in order to improve the friction characteristics etc.
For example, Patent Document 1 discloses a method of production of a clutch facing comprising adhering a thermosetting resin composition composed of a thermosetting resin such as a phenol resin, urea resin, melamine resin, and epoxy resin in which a rubber ingredient is mixed onto a base material fiber, further adhering a binder composition containing a rubber compound, pre-forming this base material fiber into a spiral shape or laminate shape, then hot pressing the obtained pre-formed article.
However, the clutch facing obtained by the art of the above Patent Document 1 is not sufficient in heat resistance (for example, large in an amount of change of friction characteristics after heat aging), so improvement of the heat resistance is desired.